From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/leds/leds-gpio.c | 304 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 304 insertions(+) create mode 100644 drivers/leds/leds-gpio.c (limited to 'drivers/leds/leds-gpio.c') diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c new file mode 100644 index 000000000..15eb3f86f --- /dev/null +++ b/drivers/leds/leds-gpio.c @@ -0,0 +1,304 @@ +/* + * LEDs driver for GPIOs + * + * Copyright (C) 2007 8D Technologies inc. + * Raphael Assenat + * Copyright (C) 2008 Freescale Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct gpio_led_data { + struct led_classdev cdev; + struct gpio_desc *gpiod; + struct work_struct work; + u8 new_level; + u8 can_sleep; + u8 blinking; + int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state, + unsigned long *delay_on, unsigned long *delay_off); +}; + +static void gpio_led_work(struct work_struct *work) +{ + struct gpio_led_data *led_dat = + container_of(work, struct gpio_led_data, work); + + if (led_dat->blinking) { + led_dat->platform_gpio_blink_set(led_dat->gpiod, + led_dat->new_level, NULL, NULL); + led_dat->blinking = 0; + } else + gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level); +} + +static void gpio_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct gpio_led_data *led_dat = + container_of(led_cdev, struct gpio_led_data, cdev); + int level; + + if (value == LED_OFF) + level = 0; + else + level = 1; + + /* Setting GPIOs with I2C/etc requires a task context, and we don't + * seem to have a reliable way to know if we're already in one; so + * let's just assume the worst. + */ + if (led_dat->can_sleep) { + led_dat->new_level = level; + schedule_work(&led_dat->work); + } else { + if (led_dat->blinking) { + led_dat->platform_gpio_blink_set(led_dat->gpiod, level, + NULL, NULL); + led_dat->blinking = 0; + } else + gpiod_set_value(led_dat->gpiod, level); + } +} + +static int gpio_blink_set(struct led_classdev *led_cdev, + unsigned long *delay_on, unsigned long *delay_off) +{ + struct gpio_led_data *led_dat = + container_of(led_cdev, struct gpio_led_data, cdev); + + led_dat->blinking = 1; + return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, + delay_on, delay_off); +} + +static int create_gpio_led(const struct gpio_led *template, + struct gpio_led_data *led_dat, struct device *parent, + int (*blink_set)(struct gpio_desc *, int, unsigned long *, + unsigned long *)) +{ + int ret, state; + + led_dat->gpiod = template->gpiod; + if (!led_dat->gpiod) { + /* + * This is the legacy code path for platform code that + * still uses GPIO numbers. Ultimately we would like to get + * rid of this block completely. + */ + unsigned long flags = 0; + + /* skip leds that aren't available */ + if (!gpio_is_valid(template->gpio)) { + dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n", + template->gpio, template->name); + return 0; + } + + if (template->active_low) + flags |= GPIOF_ACTIVE_LOW; + + ret = devm_gpio_request_one(parent, template->gpio, flags, + template->name); + if (ret < 0) + return ret; + + led_dat->gpiod = gpio_to_desc(template->gpio); + if (IS_ERR(led_dat->gpiod)) + return PTR_ERR(led_dat->gpiod); + } + + led_dat->cdev.name = template->name; + led_dat->cdev.default_trigger = template->default_trigger; + led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); + led_dat->blinking = 0; + if (blink_set) { + led_dat->platform_gpio_blink_set = blink_set; + led_dat->cdev.blink_set = gpio_blink_set; + } + led_dat->cdev.brightness_set = gpio_led_set; + if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) + state = !!gpiod_get_value_cansleep(led_dat->gpiod); + else + state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); + led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; + if (!template->retain_state_suspended) + led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; + + ret = gpiod_direction_output(led_dat->gpiod, state); + if (ret < 0) + return ret; + + INIT_WORK(&led_dat->work, gpio_led_work); + + return led_classdev_register(parent, &led_dat->cdev); +} + +static void delete_gpio_led(struct gpio_led_data *led) +{ + led_classdev_unregister(&led->cdev); + cancel_work_sync(&led->work); +} + +struct gpio_leds_priv { + int num_leds; + struct gpio_led_data leds[]; +}; + +static inline int sizeof_gpio_leds_priv(int num_leds) +{ + return sizeof(struct gpio_leds_priv) + + (sizeof(struct gpio_led_data) * num_leds); +} + +static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct fwnode_handle *child; + struct gpio_leds_priv *priv; + int count, ret; + struct device_node *np; + + count = device_get_child_node_count(dev); + if (!count) + return ERR_PTR(-ENODEV); + + priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL); + if (!priv) + return ERR_PTR(-ENOMEM); + + device_for_each_child_node(dev, child) { + struct gpio_led led = {}; + const char *state = NULL; + + led.gpiod = devm_get_gpiod_from_child(dev, NULL, child); + if (IS_ERR(led.gpiod)) { + fwnode_handle_put(child); + ret = PTR_ERR(led.gpiod); + goto err; + } + + np = of_node(child); + + if (fwnode_property_present(child, "label")) { + fwnode_property_read_string(child, "label", &led.name); + } else { + if (IS_ENABLED(CONFIG_OF) && !led.name && np) + led.name = np->name; + if (!led.name) + return ERR_PTR(-EINVAL); + } + fwnode_property_read_string(child, "linux,default-trigger", + &led.default_trigger); + + if (!fwnode_property_read_string(child, "default-state", + &state)) { + if (!strcmp(state, "keep")) + led.default_state = LEDS_GPIO_DEFSTATE_KEEP; + else if (!strcmp(state, "on")) + led.default_state = LEDS_GPIO_DEFSTATE_ON; + else + led.default_state = LEDS_GPIO_DEFSTATE_OFF; + } + + if (fwnode_property_present(child, "retain-state-suspended")) + led.retain_state_suspended = 1; + + ret = create_gpio_led(&led, &priv->leds[priv->num_leds++], + dev, NULL); + if (ret < 0) { + fwnode_handle_put(child); + goto err; + } + } + + return priv; + +err: + for (count = priv->num_leds - 2; count >= 0; count--) + delete_gpio_led(&priv->leds[count]); + return ERR_PTR(ret); +} + +static const struct of_device_id of_gpio_leds_match[] = { + { .compatible = "gpio-leds", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_gpio_leds_match); + +static int gpio_led_probe(struct platform_device *pdev) +{ + struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct gpio_leds_priv *priv; + int i, ret = 0; + + if (pdata && pdata->num_leds) { + priv = devm_kzalloc(&pdev->dev, + sizeof_gpio_leds_priv(pdata->num_leds), + GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->num_leds = pdata->num_leds; + for (i = 0; i < priv->num_leds; i++) { + ret = create_gpio_led(&pdata->leds[i], + &priv->leds[i], + &pdev->dev, pdata->gpio_blink_set); + if (ret < 0) { + /* On failure: unwind the led creations */ + for (i = i - 1; i >= 0; i--) + delete_gpio_led(&priv->leds[i]); + return ret; + } + } + } else { + priv = gpio_leds_create(pdev); + if (IS_ERR(priv)) + return PTR_ERR(priv); + } + + platform_set_drvdata(pdev, priv); + + return 0; +} + +static int gpio_led_remove(struct platform_device *pdev) +{ + struct gpio_leds_priv *priv = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < priv->num_leds; i++) + delete_gpio_led(&priv->leds[i]); + + return 0; +} + +static struct platform_driver gpio_led_driver = { + .probe = gpio_led_probe, + .remove = gpio_led_remove, + .driver = { + .name = "leds-gpio", + .of_match_table = of_gpio_leds_match, + }, +}; + +module_platform_driver(gpio_led_driver); + +MODULE_AUTHOR("Raphael Assenat , Trent Piepho "); +MODULE_DESCRIPTION("GPIO LED driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:leds-gpio"); -- cgit v1.2.3-54-g00ecf